Dirty Oil

By Katherine Bourzac

Description text

Equipment used by oil-sand miners includes tractors with top-mounted radiators and cooling fans to protect their engines from oil particles and sludge, thousand-metric-ton shovels, and the Caterpillar 797. This colossal dump truck weighs more than 500 metric tons when empty. When its tires wear out after about a year, they are reused as cattle feeders.

Producing crude oil from the Alberta sands is an energy-­intensive process. Giant digging and transportation machines use commensurately large amounts of fuel. Refining and welling technologies consume roughly 300 cubic meters of natural gas per barrel of recovered oil. Environmental watchdogs estimate that, as a result, producing a barrel of oil from the Alberta sands releases two to three times the volume of greenhouse gases that traditional oil production would. By 2015, production from the oil sands is projected to release 94 megatons of greenhouse gases.

Oil sand retrieved from surface mining is crushed and then moved to a processing plant via "hydrotransport." As the sand, mixed with water, tumbles through transport pipes, the clumps of bitumen, sand, and water begin to loosen.